Die making



S. WADSTEN DIE MAKING Filed Dec. 28. 1929 INVENTOR BY 5. M41757 /V.

ATTORNEY iatentd Get. 3 1, 1933 15m MAKING Sten Wadsten,- Bloomfield, N. J assignor to Westinghouse =Lamp Company, a corporation of Pennsylvania Application'becember 28, 1929 Serial No. 417,187

1 can. (01. 49-79) The present myene n' relates to an improvement machines for helically winding. afilamentary; Wire as shown and. described in Patent No. 15370;}99 and relates more particularly to a 5 ,-method and apparatus for making a coil winding die for use in suchmachines.

the above mentioned-patent a machineis shown for coiling a fine hair -like Wire to a helical form; in the absence of a mandrel and particularly -for theproduction of lengths of coiled wire to serve as fiiaments for-incandescent electric lamps.

The said machine comprises mechanism formoving aswire through a given path by tangential engageinent-with a pair. of oppositely disposed ..driving rollers which propel the .wire endwise into;

'acavity die which is so constructed that the wire issues therefrom in the form of a-tcontinuous helix. Means-are -provided for cuttingthe helix into sec tions of proper lengths toconstitute filaments v .for incandescent electric lamps.

tioned to receive the wire from the driving rolls,

thebottom of, the cavity being inclined or, grooved.v

the coil or helix which issues. from the die are consequently spaced a given distance apart and the helix is, therefore, provided for. a certain.

di ameter and pitch depending upon the dimen "'sionsof the spacer member and the radius of curvature-of the effective surface of the cavity as wellas the position of the die with the-driving rolls.

respect to g nthe manufacture of coiled filamentary bodies whichserve as electrical resistance elements when. used as lamp filaments, it is essential to exercise extreme accuracy in. the formation of the coils, sinceeach filament or coiled section mustbe made 40 ,in accordance with specified dimensions so that e "eachcoiled section-will have a length of wire therein equal to the succeeding coiled section,

Furthermore, the diameter of the coilas well as dimensions and proportions is known as; the

. {,9 .rating so that a coiled section for a given rating.- must be made in-- accordance witha predetermined setlof dimensions. For examplaa filament for a.,60 Watt 115;;volt lamp must contain a; length of wire of 517 mm. it must have a diameter of 5 -.0l08 inches and the coiled section must contain The die is so arranged that the cavity is posis 398 turns per inch. ,The diameter of the wire also varies in filaments of different wattage, lamps and the diameter of the wire of a coiled filament of a watt lamp is preferably .0018? inches.

It will. be obvious; that inorder to produce a lamp filament and hold the coil formation to the required proportions and. dimensions it is necessary'to accurately form .thecoil winding die and to provide accurately adjustablemeans for holdingthe said die ina given relation to the path of movement of the wire thereto. In the above mentioned' patent a coil winding dieis shown and described; aspreferably consisting ,of an extremely, hard material such as a diamond. .A diamond die, althoughhaving indefinite life, is difficult to produce and owing to variations in the properties of a diamond, it is very often brittle to the extent that portions :of thecoilwinding lip are broken off rendering the die inoperative for the purpose intended. 1

As set forth in the said patent the coil winding die. maybe constructedfrom hardened steel but inasmuch ,as the wire passing over the die results in excessive wear, it is necessary .to replace the steel die at shorter intervals thanis necessary with a diamondzdie. Ordinarily the replacement of onedie foranother would offer a considerable disadvantage sinoe whenapplying a die into po-,-

sition for. the winding ,of a coiled filament; it is necessary to-adiustthe die in several planes until the "cavity isaccuratelylocated in such position that the diameter and pitch of the coil produced .will be in accordance with the data supplied for the rating of the particular lampiforwhich thefilament is tobe useds; I When using adiamonddie-the die remains in the' machine for such a l ong period that the amount of labor and inconvenience involved in a change from-onedie to another is negligible. A steel die," although easier to-produce, must bechanged at comparatively short intervals and the advantage given by the facility accompanyfi ar i o h of t turns of the must J ing the production of the die-1s'reduced'bythe.

i5 be uniform.

time and labor involved in replacing -the same.

It will further be understood in' order to wind fine filamentary wire to'helicalform in accord ance withgiven'dimensions, it is necessary to exercise considerable care "as above mentioned in accuratelylocating the die cavity When it is necessary, therefore to change the die owing to Wear, difficultyis encountered in. replacing a new die' in exactly the same position as thatpre viouslypccupied by the removed .die.

In my copending application Serial No. 242,715

filed December 27, 1927 for Method of producing V and setting coil winding dies, apparatus is shown wherein a die may be made or" steel while 13081- tioned in a holder and so arranged that the die, when finished may be inserted into the coil winding machine in exactly the same'position as occupied by a die which was produced by moving a matrix against a soft metal die blank and compressing the material of the blank to form a die cavity. Although this method is satisfactory it requires a time interval and necessitates considerable care as well as the use of a cerain amount of apparatus.

It is an object of the present invention to facilitate the die forming operation.

Another object of the invention is to provide a method of forming a die from a fusible material in a rapid and eflicient manner.

Another object of the invention is to provide a coil winding die of vitreous material.

Another object of the invention is to provide a coil winding die having a hard smooth glossy surface.

Other objects and advantages of the invention will be more fully understood as the description proceeds.

In accordance with the present invention a coil winding die is produced by moving a matrix into contacting relation with a die blank consisting of a vitreous material such as glass, while the said blank is in a plastic condition. In practicing the invention a coil winding die is made, for example, for the formation of filaments for 40 watt lamps. This die may be made of steel or other hard material and adjusted in a holder in the machine until it is in the exact position to wind coils for the rating. required.

While in its adjusted position in the holder it i is moved into contact with the end of a matrix blank and forced thereagainst until an impression of the end of the die is formed in the matrix blank thus producing a matrix member. This matrix member is then held in a given position and a die rod having a tip consisting of a vitreous "material is positioned for movement into contact with the matrix. The vitreous material may be heated by a fine pointed flame until its exposed portion is in a plastic state at which time it may be moved into contact with the matrix so that -=thevitreous or die portion of the die blank is formed to constitute a cavity die and ready to be positioned in a coil winding machine.

By reason of the present method a die may be produced in a rapid and efiicient manner so that if during the winding of a quantity of coiled filaments it becomes necessary to renew the die, such operation may be accomplished with a minimum loss of time.

The invention will be more fully understood by reference to the accompanying drawing in Which,

' Fig. 1 shows a portion of a coil winding machine partly in section with the coil winding die in position.

Fig. 2 is a side elevational view showing apparatus for moving a dieblank in contact with a matrix for a die forming operation.

Fig. 3 is an enlarged view of a master die and a matrix member in contact to form the wire bending cavity in a matrix.

Fig. 4 is a view showing the master die and matrix after the latter has received its wire bending cavity, 7 f

Fig. 5 is a side elevational view of a portion of a matrixmember partly in section.

Fig. 6 is a top end view of a matrix member showing the dieforming cavity.

Fig. 7 is a side elevational view partly in section showing a die blank with a die cavity formed in a vitreous portion at its end.

Fig. 8 is an end view of the die shown in Fig. 7 and Fig. 9 in an enlarged fragmentary cross sectional view showing the formation of a coil winding die with a portion of a coiled wire.

Although the present invention may be practiced to produce a cavity die for use in coil winding. machines Where adjustment is necessary it is preferable to practice the invention for producing a die in a predetermined position with respect to a machine element for application to a coil winding machine.

Fig. 1 shows a portion of a coil winding machine comprising a holder 10 hinged at 11 to a spindle 12 which spindle is journalled in a suitable bear ing on the body or" a coil winding machine. By reason of the pivot 11 and the spindle 12 it is possible to move the casing 10 in a vertical and a horizontal plane and adjust a die 13 with relation to wire driving rollers or rolls 14 and 15 which propel a Wire 16 against the die 13. The die may comprise a die rod 17 and since it is essential to provide a more accurate adjustment of the die than may be accomplished by the above mentioned vertical and horizontal adjustment, a sleeve 18 is provided to receive the die rod 17 which sleeve is fitted in a suitable bore 19 in the casing 10.

The sleeve 18 in which the die or die rod is positioned may be termed a die sleeve or collar and a set screw 21 is provided to engage a notch or depression 22 in the die rod to hold it in a predetermined relation to the sleeve. An adjustment of the die rod about its longitudinal axis may be obtained by a rotary movement of the sleeve 18. For this purpose the sleeve is provided with a yoke 23 having a split head 24 by means of which a clamping screw 25 secures the yoke to the saidsleeve 18. Arms 26 and 27 extend downwardly from the yoke and are posi-- tioned on opposite sides of a control arm 28 infrom the wire driving rollers 14 and 15. For the purpose of clamping the sleeve in its final position the casing 10 is split and clamping screws 32 are provided. 1

The above tool or die holder constitutes part of a coil winding machine and it is thought that the 1 above description is sufiicient for the present purpose in showing the die holder and the means may be adjusted with relation to the holder. In

producing a die for application to the holder such as that shown in Fig. 1 a die rod 17 may be provided with a tip 33 consisting of a vitreous material suoh as glass, good results having been ob-' "render it sufiiciently plastic to take an impresany suitable manner as for examplaby a heat resisting cement34 As shown in Figs. 5 and '6' a matrix 35 is provided having a die'formingrecess 37, the bottom surface 'of which is provided with a raised=portion or fini 39; The matrix is employed "to. receive the tip '33 when'the same-has been: rendered plastic so'that the said tip" will takethe reverse-form of the'recess 37 and a die forming cavity 39 willbe producedf with a coil winding up 41 'in the proper relative position.

The'*'operation of' 'bringingthe matrix and the, vitreoustipof 'thedie blank-into contact will be more clearly understood by reference ilQFlg. 2-

which shows an apparatus comprising a holder '42 to're'ceive a. sleeve 18" which is substantially a duplicate of the sleeve l8'and in whichmay be disposedasie rod- 17 having a vitreous die blank at="'o'ne end thereof. Asetsc'rewZl engages a seat 22"toiioldth'e die ro'd'in'a given positionwith respect to the sleeve 18' and the saidfsleeve is positionedintheholder 42 and secured by a set screw 43. Adjacent to the holder 42 is positioned a horizontal bearing bracket 44 having a bearing 45 in which a slidable holder 46 is positioned.

The holder 46 is provided with a bore 47 in which the matrix 35 is positioned. A set screw 48 is provided to secure the matrix in position and the bearing bracket 44 is provided with a slot 49 to permit the set screw 48 to travel with the slidable holder 46.

The matrix 35 is arranged with its longitudinal axis coincident with the longitudinal axis of the die rod so that amovement of the slidable holder will move the recess 37 of the matrix into contacting relation with the vitreous tip of the die rod.

For the purpose of forming the vitreous tip to the shape of the matrix, a burner nozzle 51' is provided to direct a fine needle-point flame 52 against the surface of the vitreous tip 33 to sion.

The slidable holder 46 is actuated to move the matrix 35 by means of a handlever 53 having a slot 54 to receive a pivot pin 55 provided in -a projection 56 integral with the slidable holder.

The lever 53 is pivoted at 5'7 and is provided with a link 58 pivotally attached at 59 to one end of a valve arm 61 of a valve 62 controlling the gas flame 52. While the arm 53 is in its retracted or initial position the link 58 operates to direct the needle flame 52 against the vitreous die blank. As the arm 53 is moved to advance the matrix the valve 62 is closed to remove the flame and as the matrix advances to the position shown in dotted lines the softened end of the die blank is impressed with the die formation.

It will be understood that the flame 52' may not be entirely extinguished but lowered to a mere pilot light so that when the lever arm 53 returns the. matrix, the flame may then issue from the nozzle 51 ready to heat another positioned die blank. The bearing bracket 44 is provided with an adjustable stop 63 so arranged as to terminate the advance movement of the slidable holder and thus form the effective die face in a predetermined position as indicated by the arrows X with respect to the set screw 21. Thus whena die has been used and has worn or .does not give the proper winding, the die rod 1'? may be inserted in the sleeve 18' and the end softened and a' new diev formed immediately; I

It will be'understood that althouglf'a'njew'diief rod maybe employed having a new 'tip, itfis in manycases, only necessary to reheat the' endl of the vitreous tip having the die formation to; renewth'e die form. Inasmuch as the dieis made in exactly the position that it isused" the jnew die may be readily set up in the machine without further adjustment since it'occupies the exact position of t e diepreviously employed.

' It is desirable'to make the'matrix35'jfrom"a1 die'which is actually used to' wind coil s'to a given rating data as for examplea die'may be made'of steel or other hard material and placed in' a,

-machine to wind coils and adjusted and ground, if necessary, until it is exactly right forthe wind ing of coiled filaments fora givenwattage. die'which in Figs. 3 and '4 is designated byv the numeral 64' is then forced into contact withone end of the matrix rod 35 untilanimpression.

is .made as shown in lf'igfB. When the die 64 is removed, as shown in Fig. 4 the"recessif37 and the fin 38 has been formed and the matrix 35 is readyto'be positioned in a slidable'holder 46jfor movement into contact with the softened'endofi the die blank. 7

When forming the die by a movement of the matrix toward the die blank it may be preferable to heat the matrix and for this purpose a burner is provided. It will be understood that the said burner may be operated to close off as the slidable holder advances or it may be a continuous flame of relatively low temperature to maintain the matrix heated so as not to chill the die under formation. It will also be understood that if desirable a' flame 52 may, after the die blank has been formed, operate to supply only sufiicient heat to anneal the formed 'die.

As hereinbefore set forth, coil winding dies must'obviously be produced of different dimensions for the manufacture of filaments for lamps of different wattages. The die faces are extremely small and it is often difficult to determine by inspection the particular wattage for which the die has been made. When using a vitreous material such as glass, it is possible to take advantage of various colored glasses and use a given color glass for a given wattage die so that when a definite color has been assigned to a lamp of a given wattage the selection of the proper die is facilitated and a considerable amount of time is saved.

By reason of the present invention amandrel: less coil winding machine may be operated cone tinuously and in the event that a new dieis required the same may be produced without an appreciable amount of delay.

Fig. 9 shows a perspective view on anenlarged scale of a coil winding die such as employed in connection with the present invention and it will be noted that this die includes a lip 41 and a cavity 39; 'The wire 16 is driven into the cavity and issues in the form of a series of convolutions in the form of a helix, the turns of which are separated by, the lip 41 which determines the pitch.

It will be appreciated that inasmuch as the entire action with respect to the wire and the die is a sliding or frictional engagement, it is desirable in order to avoid wear to provide a die with an extremely smooth effective surface. When employing a vitreous material such as glass or enamel composition, it is possible to provide an effective winding surface having an units broken layer or skin and when using fusible material the skin or surface layer is extremely hard and wear resistant. Heretofore in the manufacture of a diamond die for example, a reasonably smooth surface was attainable but owing to the grinding operation the cross graining of thematerial became exposed and offered a certain amount of frictional opposition to the passage of the wire thereover and caused wear.

In the case of a metallic die which is ground, the same result would occur. When forming a metallic die by pressure, it is not possible to get the glazed smooth layer since the surface of the metal is comparatively rough and remains so whether the die is formed by pressure or by grinding. When forming a die for the present purpose of a vitreous material a new article is produced in that it provides a coil bending element having the desirable continuous glazed or slippery surface giving the desirable wear resist-- ing property which, in conjunction with the fact that the said dies may be made at a more rapid rate than dies heretoforeproduced, makes the present invention a decided advance step in the art of coil winding.

Although a preferred: l bodimentjo i thejirivention is shown and described herein it 'is to be understood that modifications maybe made therein without departing from the spirit and scope of the invention as setforth in the ap pended claim.

What'is claimed is: The method of helically coiling a wire which comprises moving a wire through agiven path,

positioning a cavity die of fusible material with: the cavity in a definite relative position with respect to the path of 'inovement or" the wire to produce a helical coil or" given pitch and diameter,

interrupting the movement of the wire, positioning a cavity forming member for move nent to 

